1. Posture

Total
body muscle tone is reflected in the infant's preferred posture at rest
and resistance to stretch of individual muscle groups. As maturation
progresses, the fetus gradually assumes increasing passive flexor tone
that proceeds in a centripetal direction, with lower extremities
slightly ahead of upper extremities. For example, very early in
gestation only the ankles are flexed. Knees will flex as wrists just
begin to flex. Hip flexion, then adduction are just ahead of elbow, then
shoulder girdle flexion. The preterm infant primarily exhibits unopposed
passive extensor tone, while the infant approaching term shows
progressively less opposed passive flexor tone.

To elicit the posture item, the infant is placed supine (if found
prone) and the examiner waits until the infant settles into a relaxed or
preferred posture. If the infant is found supine, gentle manipulation
(flex if extended; extend if flexed) of the extremities will allow the
infant to seek the baseline position of comfort. Hip flexion without
adduction results in the frog-leg position as depicted in posture square
#3. Hip adduction accompanying flexion is depicted by the acute angle at
the hips in posture square #4. The figure that most closely depicts the
infant's preferred posture is selected.